browserslist support

[chaffeqa]

We want something like https://github.com/browserslist/browserslist-useragent to support "modern" build versions that tie into the webpack browserslist implementation in order to serve different builds / service workers.

It looks like this project is more supported, and has some nice features, however is lacking browserslist feature support.

Wouldnt mind looking into this, but was wondering if it's been explored already